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Gabbyp 12-27-2010 09:08 AM

After Market Parts
During the Christmas holidays the normal auto TV shows had their marathons on and what was prevalent was the number of after market parts being used. When you see AD pickups, Mustangs, Camaros, Mopars, Tri-Five replacement parts being used, I began thinking has modern technology made all this possible. All of these body panels require presses and stamping dies. Any stamping press of the proper tonnage will do but what about the dies. Are they original dies that were scrapped years ago and found? Are these dies made from original drawings that have been laser or digitally scanned and converted to CNC data to run mills and lathes? Do they scan existing parts and convert to CNC data? Do they use newer metallurgy for die materials that have a limited production run but cheaper and easier to make? I have seen how the aerospace companies used data to deposit plastic into objects that are used to make molds for casting parts or other technologies that I donít even know about. I am wondering if any of this technology is being used to make these parts more available today than before. I am not commenting on the overall quality, because I donít know, but the more I see of these parts being used, the quality and overall costs have to be good or people wonít buy. Any thoughts on this topic.

1971BB427 12-27-2010 09:56 AM

Yeah I can give you an earful on this subject since I finished a fairly extensive rebuild of my '71 Camaro in June. Aftermarket parts are not all the same! Some are junk that's way too thin, and ill fitting, and even the best brands can produce crap.
I was told to use certain suppliers, and that all their stuff was good. Some even advertise that their items are exact repros of factory parts, but that's just baloney. I found that there's only a few makers over in China doing all the body panels, and that ALL of them use new dies. The difference is the distributr. Some companies send their reps over to check everything before accepting the parts. Those companies end up providing a good product, because they do their own QC, while others negotiate a price and just buy what they get, then sell it. I know one company that has a huge number of cowl induction hoods for 2nd gen Camaros that are ALL off center, and they simply put them back on the shelf when someone returns them for defect, then resell it until it goes to someone who doesn't notice the 1/4" offcenter rib down the cowl.
When doing my Camaro I had to open up almost every hole in the frontend sheetmetal to allow parts to mate. Some holes were so far off that I couldn't open them up, and ended up cutting the brackets off and rewelding them in the correct alignment. My brackets from fenders to firewall had to both be chopped and reloacted. I also found that all the sheetmetal was much thinner than stock. So much so that the first time I closed my hood I dented it while pushing it down to latch! I had to drill holes in the hood and weld in a thin sheet behind that area above the latch to ensure it would be strong enough to hold when pushing it down.
I will say that most cast and machined parts I got (regardless of maker) fit perfectly, and looked exactly like originals. Interior repops were also of good quality with PUI, but not sure of all brands.
I found that National Parts Depot was the absolute best seller of quality parts. I spoke with a rep there, and they don't purchase anything without visiting the maker's plant and inspecting all parts before signing the check. Never had any issues with anything I bought from NPD.

Gabbyp 12-29-2010 09:00 AM

Thanks 1971BB427 for your comments on your experiences with after markets parts. Itís interesting that only a few companies in China make all the stamped parts with new dies. However as stated, if the parts are QCíd correctly with the proper gauge steel then they can be acceptable. The costs are lower in China as everybody knows why. This goes back to my original question is how do they make the dies. Old school or new technology? Iím just curious about the process.
I also notice that the large number of aluminum heads on the market today in all of their variations that technology has had to play a role in their manufacture. Iím not commenting on the quality or non quality of any foreign made heads. Aluminum heads especially made in the USA must be using computers for 3D modeling, fluid dynamics, CAD/CAM usage for prototype development before committing to production, new production casting machinery allow these products to come to market sooner? The reasonable costs, manufacturer selections and performance output of these heads are fantastic that technology has had to have been used somewhere in the process. I am intrigued and would like to know more how technology is use today in all aspects of our hotrod industry.

st3gamefarm 12-29-2010 08:03 PM

On a recent '69 Z-28 project, we went through 3 sets of wheel opening mouldings, 2 sets of rocker mouldings, 4 Dash pads, 2 instrument clusters,
2 center consoles, 4 pairs of taillights, 3 rear bumpers, and 2 front bumpers,
1 windshield, 4 door glasses, 2 carpet sets, and 2 body mount kits.
(All brand new aftermarket parts), before we found things that were even half azzed acceptable, but still not really good enough. Also had a couple of package trays, and a rear seat back that were all screwed up.
But at least we were allowed to pay th' shippin both ways. :rolleyes:

I've found that there is not much difference between the different vendors
or the parts they sell.

Currently workin' on a '55 chevy, Bought 2 birds for th' hood, (from a company that begins with a D) neither fit, (but were different in the way that they didn't fit) but the origional fits good. You would think that for $300 the dang thing would at least come close.
Same for th' gas flap rubbers, Th' screws that come with th' new ones are not the proper style screws, but when ya got no screws, an' no time to order th' right ones from Aircraft Spruce, yer kinda stuck.

1971BB427 12-29-2010 11:54 PM

I'm having way less trouble building my Austin gasser than rebuilding my '71 Camaro! At least I can fabricate any parts I need instead of having to try and match less than perfect repop parts! :)

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